Digging machine



July 14, 1959 w. M. AMTHoR ET AL 2,894,341

DIGGING MACHINE Filed Oct. 5. 1955 8 sheets-sheet 1 Wil/iam M Amt/mr V/'n cam* Kosuga IN V EN TORS BY W15/wy HMO):

July 14, 1959 Filed Oct. 5, 1953 Fig. 2

W. M. AMTHOR ETAL DIGGING MACHINE 8 Sheets-Sheet 2 Wil/iam M. Am thor I/incenf Kosuga IN V EN TORS BY d/way me);

July 14, 1959 w. M. AMTHOR 'E1-AL 2,894,341

DIGGING MACHINE 8 Sheets-Sheet 5 Filed Oct. 5, 1953 Wil/fam M. Amr/wr V/ncen/ Kosuga L INVENTORs` 9 BY all ...L l .|...l

Julyl 14, 1959 w. M. AMTHQR ET AL 2,894,341

' DIGGING MACHINE 8 Sheets-Sheet 4 Filed oct. 5, 1953 Wil/iam M. Imlhorv V/ncen Kosuga l JNVENToRs BY MWWMW July 14, 1959 w. M. AMTHoR ETAL DIGGING MACHINE Filed Oct. 5, 1953 IILIIIJ n Wil/iam. M. Am'fhar m .Sm

July 14, 1959 w. M. AMTHOR ETAL DIGGINGMACHINE s sheets-sheet e Filed Oct. 5. 1953 vNN L. www@ Aww. a EN MM m, mm wn u w .Mw w

mmv mS Q .mi

W. M. AMTHOR ET AL July 14, 1959 DIGGING MACHINE 8 Sheets-Sheet 7 Filed oct. 5, 1953 INVENToRs .MK m4! .mm mm WV IWW HMM; I

S .Em

NNI

-Fi'g. 20

July 14, 1959 w. M. AMTHOR ET AL 2,894,341

DIGGING MACHINE Filed Oct. 5, 1953 A 8 Sheets-Sheet, 8

1 Wil/iam M. Amr/Jar Vi n cen f Kosuga IN VEN T035 United States Patent O DIGGING MACHINE William M. Amthor, Walden, and Vincent Kosuga, Pine Island, N.Y.

Application October 5, 1953, Serial No. 384,242

3 Claims. (Cl. 3'7-97) This invention relates to a digging machine and more specifically provides a self-propelled lditching machine.

An 4object off this invention is to provide a digging machine having a ditch digging element rotatably mounted thereon wherein a ditch may be dug while the machine progresses over the ground surface.

Another object of this invention is to provide a digging machine which has laterally -adjustable ground engaging driving tracks wherein the digging machine may be utilized to drain swamplands, dig pipelines, deepen small streams and dig irrigation ditches wherein the terrain to be ditched would necessitate traction surfaces at a point remote from the digging area.

A further object of this invention lis to provide a digging machine having a rotary ditching element including a plurality of buckets or scoops which are changeable wlherein various shapes and sizes of ditches may be excavated.

Yet -another object of this invention is to provide a digging machine including a rotary ditching element having a hollow center portion and a conveyor thereon which 4discharges the dirt excavated from a ditch to a suitable truck or pile the dirt at a point on either side of the digging machine and an adjustable distance from the ditch as may be desired.

A still further object of this invention is to provide a digging machine including a rotary ditching element pivotally secured to the rear of la traction unit and having means for vertically adjusting the ditching element wherein the depth of the ditch may be set.

Another important object of this invention is to provide a digging machine including a tractor unit, a ditching element and a conveyor and means for driving each of the elements independently or simultaneously as may become necessary in the ditching process.

Yet another important objects of this invention is to provide a digging machine that is self-propelled for transportation and digging and which is simple in operation, efficient in operation, ilexible in utility and well adapted for the purposes intended.

These together with other objects and advantages which will become subsequently app-arent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a side elevational View showing the structural details of the tractor unit and the ditching element;

Figure 2 is a top plan view of the structure of Figure 1 showing details of the digging machine with the traction members in their innermost positions;

vFigure 3 is a transverse, vertical section taken substantially along section line, 3-3 of Figure 2 showing details of construction of the ditcher element;

Figure'4 `is an Venlarged view of a portion of the ICC 2 rotary ditcher element showing the particular construction of the buckets or scoops thereon;

Figure 5 is a detail section showing an enlarged center portion of the rotary ditcher element and the relationship of the rotary ditcher element and the discharge conveyor;

Figure 6 is a detail section taken substantially along section line 6-6 of Figure 4 showing the particular construction of the ditcher element bucket or scoop;

Figure 7 is an enlarged perspective view showing one of the ditcher buckets or scoops;

Figure 8 a top plan schematic diagram showing the track driving means and the means for extending the tracks to their outermost positions as shown in phantom;

Figure 9 is a top plan detail view showing the 'extensible system and cylinders which are used to move the tracks outwardly and inwardly, taken substantially along the section line 9 9 of Figure 11;

Figure 10 is a top plan view showing the extensible track supporting members;

Figure l'l is a transverse, vertical section taken sub- Y stantially along section line 11-11 of Figure 10 showing details of the telescopically arranged track supporting members;

Figure 12 is a top plan view showing the driving means for the rotary ditcher element and the gear reduction unit therefor;

Figure 13 'is a longitudinal, vertical section taken sub stantially along section line 1.3-13 of Figure 2 showing details of the boom pivotal connection and the vertical adjustment therefor including vthe vertical slides for move ment of the ditcher element;

Figure 14 is an enlarged detail perspective view of the vertical guide and slides mounted thereon for movement of the end of the ditcher mounting boom;

Figure l5 is a schematic detail view showing the expansible cylinder and piston used for raising and lowering the remote end of the ditcher supporting boom;

Figure 16 is an end view of the rear guide member on the ditching element boom for forming a ditch having even side Walls;

Figure 17 is a transverse, top plan section taken substantially along section line 17-17 of Figure 16 showing details of construction ofthe rear member or guide on the ditching element boom;

Figure 18 is a top plan view of the conveyor mounted in the center of the rotary ditching element including the drive means and adjustment means therefor;

Figure 19 is a'longitudinal, vertical section 'taken substantially along section line 19-19 of Figure 18 showing details of the conveyor and the running gear thereof; and,

Figure 20 is a diagrammatic view of the hydraulic 'control means and drive means of the various hydraulic cylinders and pistons and hydraulic motors.

Referring now specifically to Figures l kand 2 of the drawings, it will be seen that the power unit of this digging machine generally designated by the numeral 10 includes a tractor unit 12 having the usual seat 14, radiator 16 and other conventional structure such as a canopy (not shown) which is supported by the standards 18. The tractor 12 is mounted on a generally rectangular frame 20 by suitable upstanding members 22 having a pivot axle therethrough and suitable springs 24 spaced therefrom for resiliently supporting the tractor on the Vframe 20.

Asbest seen in Figures 8-11 as well as in Figures 1 and 2, the tractor 12 has a rotatable driving axle 26 with a sprocket 2S on each end thereof and the yframe 20 includes two pairs of bearing members 30 adjacent the rearmost corners thereofffor a purpose described heremafter. The 'frame Y20 includes transversely 'extending tubular members 32 -at the remote transverse edges thereof and a pair of polygonal track supporting members 34 are teleScopically received in the tubular members 32 and are slidable with relation to each other and along side each other. Supported on the outer ends of each pair of support members 34 is a longitudinally elongated beam 36 having an idler wheel 38 at each end thereof and an endless track 40 passing over the idler wheels 38 and a plurality of small guide wheels 42, such as found in a conventional endless tread tractor. The rearmost idler 38 includes a sprocket 44 secured thereto and rotatable therewith for driving the endless track 40 thereby propelling the device over the ground.

Each of the bearing members 30 has a rotatable bearing element 46 for receiving a polygonal drive shaft 48 in slidable relation and a sprocket 50 is held captive between lthe bearing members 30 and non-rotatably and slidably mounted on the polygonal drive shaft 4S. Sprocket chains 52 connect the sprocket 28 and the sprocket 50 for driving the polygonal drive shaft 48, and 4a sprocket chain 54 connects a sprocket 56 on the drive shaft 48 to the sprocket 44 connected to the idler gear 38 for driving the treads or tracks 40.

Referring now specically to Figure 9, it will be seen that each of lthe elongated beams has a piston rod 58 pivotally secured to the upper surface thereof by suitable pivot brackets 60 and a pair of cylinders 62 are pivotally secured to the undersurface of the frame 20 and suitable flexible conduits 64 are connected lto each end of the double acting piston and cylinder arrangement for contracting and expanding the piston rods 58 thereby moving the elongated members 36 and the endless tracks 40 away from or towards each other. A hydraulic pump -66 is positioned on the front of the tractor 12 and driven thereby for supplying hydraulic Huid-under pressure to the valve casing 68 adjacent the seat 14 of the tractor 12. A plurality of handles 70 are positioned on the valve casing 68 for manipulating valve fluid and pressure to the various hydraulic lines. One of the exible hydraulic lines is connected to the flexible line 64 for actuating the piston rod 58 and cylinder 62. The operation of the tractor unit 12 will be readily understood. The operator starts the tractor and by a suitable clutch and gearing means, all of which is conventional', turns the axle 26 and sprockets 28 thereon. The sprockets 28 move the sprocket chains 52 thereby rotating sprockets S and both polygonal drive shafts 48 which in turn rotates the sprockets 56, sprocket chain 54, sprockets 44 and moves the endless track 40 about the idler wheels 38 and 42, all in an obvious manner. Y

When it is desired to extend the tracks 40 to `a 'greater lateral width, the appropriate valve handle'70 is manipulated, thereby admitting pressure to the inner ends of the cylinders 62 thereby forcing the piston rods 58 outwardly ywhich moves the supporting members 34 in relation to each other in the tubular member 32 and slides the polygonal drive shaft 48 through the bearing members 46 and the sprocket 50 wherein the sprocket 50 will transmit rotational motion throughout the entire length of the polygonal drive shaft 48 and the relationship of the support members 34 is maintained, due to the double tubular construction 32 and the endless tracks 40 Will be moved about the idler pulleys 38 and 42'regardless of the adjusted position of the tracks in relation to each other. ln order` to contract Vthe tracks 40, the proper handle is manipulated, and pressure is released from the inner ends of the cylinders 62 and admitted to the outer ends of the cylinders 62 thereby engaging the other side of the double acting piston inside of the cylinder 62 and contracting the piston rods 58 towards the cylinders 62. The support members 34 are then telescoped inside of the tubular member 32 and the polygonal drive shaft 48 slides through the polygonal hub of the sprocket 50 and through the polygonal bearing 46 wherein the device may be operated at -any adjusted position of the tracks 40. Obviously, the tractor is equipped with suitable brakes and clutches for guiding and operating the tracks which are conventional in the tracktype tractors.

Now referring to Figure 13, it will be Seen that a pair of vertical I-beams 72 are secured to the rear edge of the frame 20 by suitable welding and extend vertically upwardly therefrom in lateral spaced relation. The rearmost flange of the I-beam 72 forms a guide for a slide member 74 which has reverse bent ends 76 secured around the flange of the I-beam 72 for vertical sliding movement thereon. As will be seen in Figure 14, the slide 74 has upper and lower projecting ears 78 and 80 having ,an aperture in each one designated by 82 thereby forming a pivot axis for a purpose described hereinafter.

As best seen in Figure l, each of the vertical I-beams 72 is provided with a pulley 84 Iat the upper ends thereof which is mounted in a suitable U-shaped member 86 which encloses the fupper edge of the pulley 84. The upper ends of the vertical beams 72 are connected to the forward end of the frame member 2.0 by suitable braces 88 thereby providing a reinforcement for the vertical beams 72.

As best seen in Figure 13, each of the vertical beams 72 is provided with a bracket 90 on the rear flange thereof for pivotally securing a piston 92 thereon and a piston rod 94 is pivotally attached to the ear 78 by a suitable pin or bolt 96 passing through the aperture 82 in an obvious manner. Suitable ilexible conduits 98 which are similar to the flexible conduits 64 are attached to opposite end portions of the cylinder 92 for operation of the double acting piston on the end of the piston rod 94. It will be understood that by suitable actuation of valve handle 70, pressure may be admitted into selected ends of the cylinders 92, thereby extending or retracting the piston rods 94 and moving the slide 74 vertically on the I-beam 72.

v therefrom with a double pulley 104 on the end portion thereof. It will be noted that the piston 100 is `rigidly secured to the frame 20 and a pulley 106 is secured to the frame in lateral spaced relation to the cylinder 100 and anchor eye bolts 108 are secured to the frame 20 in closely spaced relation to the cylinder 100. A cable 110 has end portions secured to the eye bolts 108 and has portions extending over the double pulley 104 and threaded through respective pulleys 106 and 84 and extending rearwardly therefrom for a purpose described hereinafter. It will be understood that by proper manipulation of the -Valve handle 70, fluid pressure may be admitted to the cylinder 100 through -the llexible uid conduit 112 which is similar to the flexible conduit 64, thereby extending the piston rod 102 and moving the pulleys 104 upwardly, thereby exerting a strain upon the cable 110, the significance of which will become readily apparent hereinafter.

Pivotally secured to the vertical slide 74 is a boom generally designated by the numeral 114. The boom 114 extends rearwardly of the frame 20 .and projects beyond the rearmost portion of the tracks 40. The boom 114 is generally of rectangular configuration, having side rails 116 and end rails 118. Upstanding lugs 120 are secured to the side rails 116 and pivotally support a turnbuckle 122 which is secured to the remote ends of the cable 110. It will be understood that by proper manipulation of the piston rod 102, the cable may be tensioned, thereby pivoting the boom 114 about its pivotal connection 124 to the slide member 74, thereby adjusting the angular relation between the boom 114 and the tractor frame 20. Y

Adjacent the center portion of the boom 114 is mounted a pair of lrollers 126 on the upper surface of the side rails 116 in longitudinal spaced relation and a third roller 128 is secured to the side rail 116 on the undersurface thereof and projecting downwardly at a point spaced between the rollers 126, thereby forming a threepoint contact for .a rotary element to be described hereinafter.

A rotary ditching element generally indicated by the numeral 130 is supported on the rollers 126 and 128. The rotary ditching element 130 includes a cylindrical portion 132 having inwardly extending peripheral ribs 134 adjacent remote ends -of the cylindrical portion 132 and radially extending buckets or scoops 136 are secured about the periphery of the cylindrical portion 132. The cylindrical portion 132 of the rotary ditching element 130 has radially spaced openings 138 therein which are located at the inner ends of the buckets 136. As shown in Figure 7, the bucket 136 include a pair of side members 140 having toothed upper edges 142 and an arcuate bottom 144, and the buckets 136 are tapered from their juncture with the cylindrical member 132 to their remote edges which are also toothed, as indicated by the numeral 146. The rollers 126 and 128 include a recessed portion forming a ange which rides on the surface of the rib 134 and it will be understood that the rollers 126 and 128 at opposite ends of the cylindrical member 132 and supported on the boom 114 engage opposing edges of the rib 134 thereby forming a rotary support as well as a lateral positioner for the cylindrical member 132, and necessarily, the rotary ditching element 130.

As clearly shown in Figures 3 and 5, a stationary cylindrical member 148 is positioned on the interior of the cylindrical member 132 between the projecting ribs 134 and the stationary cylindrical member 148 is held `in position by suitable brackets 150 and the upper portion of the cylindrical member 148 has angulated members 152 which are `bent at substantial right angles to the remainder of the cylindrical portion 148 and extend inwardly therefrom. It will be noted that the stationary member 148 forms a closure for the openings 138 throughout most of the rotational movement of the cylindrical member 132 except when the openings 138 are in the upper positions whereinpthe angular bent portions 152 permit material in the buckets 136 to be discharged by the action of gravity downwardly through the openings 138 onto the angulated portions 152, and the angulated portions 152 terminate at lateral edges of a conveyor generally indicated by the numeral 154. The conveyor 154 extends transversely of the boom 114 and through the center portion of the cylindrical member 132, and includes a pair of longitudinal side rails 156 which are secured to the super surface of the side members 116 of the booin 114 and the angulated portions 152 are secured to the side beams 156. Y

Referring now specically to Figures 18 and 19, it will be seen that the conveyor 154 includes an axle 158 having sprocket pulleys 160 thereon at one end and an axle 162 with sprockets 164 thereon slidably positioned in an open-ended slot 166 at the other end of the side rails 156. Screw members 168 are threadedly received in a projecting lug 170 and abut against a bearing block 172 on the axle 162 thereby forming an adjustment for the sprocket chains 174 and 176 which pass over the pulleys 164 and 160 which have transversely extending and upwardly projecting lugs 178 thereon for transporting dirt or other material therealong. A longitudinal sheet material member 180 is positioned between the side rails 156 and forms a support for the upper run of the chains 174 and 176 and .also form a guide surface for any dirt thereupon.

As will be seen in Figure 19, transversely extending braces 182 engage the undersurface of sheet metal member 180 thereby supporting the heavy loads on the bottom sheet metal member 180. It will be noted that the sheet metal member has curved end portions 184 which project around the axles 158 and 162 thereby preventing the material transported from becoming clogged in the sprocket chains.

As will be seen in Figure 18, a hydraulic motor 186 is mounted on the upper surface of one of the side rails 156 and exible conduits 188 are connected thereto and are connected to suitable valve handle 70 for manipulation thereof, thereby turning the hydraulic motor 186 and a sprocket chain 190 transmits the power of the hydraulic motor 186 to a driving sprocket 192 mounted on the adjustable axle 162 wherein the conveyor 154 may be operated. As will be understood, dirt or the like discharged from the buckets vertically down through the openings 138 is deflected by the angulated portions 152 onto the sheet metal member 180 forming the bottom of the conveyor 154 wherein the transversely extending lugs 178 move the dirt to either end of the conveyor, and it will be noted that the conveyor projects on either side of the boom 114 and the direction of discharge of the conveyor may be controlled by the valve handle 70 in an obvious manner. As seen in Figure 2, the remote ends of the conveyor 114 are supported by braces 194 which are secured to vertically upstanding brace members 196 secured to the side rails 116 of the boom 114.

As best seen in Figure 6 as well as in Figures 1 and 2, the remote end of the cylindrical member 132 is prvided with radially projecting sprocket teeth 198 and, as seen in Figure l2, a sprocket chain 200 is secured to a suitable sprocket 202 driven by a gear reduction system 204 which is operated by a hydraulic motor 206 having a sprocket chain 208 which passes over suitable sprockets 210. A guard 212 is positioned around the sprocket 210 and the sprocket chain 208 to prevent the entry of dirt and other foreign matter into Ythe sprocket chains and sprockets. Obviously, the hydraulic motor 206 is connected to the valve operating handle 70 by a suitable ilexible conduit 214.

Secured to the rearmost end of the boom 114 is a `guide 216 which is attached to the side rails 116 by a suitable bracket 218 and adjustably positioned in relation thereto by pivotal ibraces 220 which maintain the guide 216 in adjusted relation to the boom 114. The guide 216 is generally arcuate in shape and tapered from its top end to its bottom, and the bottom has a sharpened shoelike member 222 which forms the bottom of the tapered ditch and the forward surface of the guide 216 presents an arcuate face which is similar to the arcuate path of the ends lof the buckets 136 wherein the buckets will pick up any dirt or other material dug up by the guide 216. The guide 216 has suitable reinforcing ribbing 224 running throughout the length of the guide 216 on its rear surface. As will be understood, by suitable manipulation of the guide member, the particular depth and type of ditch may be determined. It will be understood that the guide may be interchanged with other particular shapes, and the buckets 136 may also be removed and replaced with other suitable buckets wherein straight sided ditches may be dug, if desired.

As shown in Figure 20, the diagrammatic outlay of the hydraulic system of the digging machine includes a ptunp 66, a reservoir tank 226 and various exible lines connecting the valve casing 68 to the various pistons 62 and 92 and the hydraulic motors 206 and 186 and suitable by-pass valves and pressure valves are interposed within the system as may *be desired or necessary.

The operation of the ditcher element will be obvious. The hydraulic motor 206 transmits power to the rotatable element 130 which rotates about the rollers 126 and the buckets 136 dig up dirt and deposit it down through the openings 138 onto the conveyor 154 and the motor 186 drives the conveyor thereby discharging the dirt to one side or the other of the digging machine, The angulated portion 152 of the stationary cylindrical member 148 derlects the dirt onto the conveyor and prevents dirt from becoming clogged up within the center portion of the rotatable element 130. The guide member 216 following the digging elements or buckets 136 picking up any loose or missed dirt and forming a guide for the end of the bucket 136. The boom 114 may be angularly adjusted by manipulation of the piston rod 102 and tensioning the cable 110, thereby raising or lowering the rearmost end of the boom 114. The inner end of the boom 114 is pivoted to the vertical slide 74 and the slide 74 and the inner end of the boom 114 may be vertically adjusted by manipulating the proper handle 70 and contracting or expanding the piston rod 94 thereby adjusting the depth of cut of the buckets 136. The particular angular relationship may be finely adjusted by the turnbuckle 122 in the cables 110, or the turnbuckle may ibe used to adjust the nal position of the rear end of the boom 114. By proper manipulation of the braces 222, the guide 216 may be adjusted for various ditches as may be desirable. Obviously, the tension on the conveyor chains 174 and 176 may be adjusted by manipulation of the threaded member 168 through the projecting lugs 170 wherein the clearances caused by wear may be taken up to provide an ecient and trouble-free operation.

In operation of the machine in practical use, the device has transplanted approximately 3,000 lineal feet of swampland to a depth of ve feet in one hours time. At this speed, the conveyor travels approximately 600 feet per minute, while the buckets and the rotatable member are turning at approximately 6 r.p.m. Further, in practical operation, the tracks are designed to be spread to a width of 20 feet when in their extended position and closed to twelve feet when in their retracted position, and it will be obvious that the device will transport itself at speeds varying from one-tenth `of a mile per hour to two miles per hour, as desired. This device is especially useful in swampland work or work around water-logged material, as the extra wide spread of the supporting and moving tracks prevent the cave-in and usual troubles encountered when the tracks are adjacent the side edges of the ditch. In the specic illustratcd embodiment, the bucket and the guides are tapered from the center to the` outer ends of the bucket, thereby digging a tapered ditch. In practical operation, the ditch which has been excavated is three feet Wide at the top, nine inches wide at the bottom and from three to ve feet deep, depending on the particular adjustment. Obviously, the device may be adjusted for other particular operations, and the buckets and guides interchanged for straight sided ditches as desired and obviously, the device may be used wherever it is desirable to excavate a ditch, whether it be a pipeline trench, an irrigation ditch or the deepening of a stream or draining a swampland.

With the well trained operator, the device may be used to excavate a ditch having a certain slope or degree of fall which is necessary in laying many pipelines and constructing irrigation ditches or drainage ditches. It appears obvious that the controls are located in a centralized location in a convenient position for the operator to manipulate same, and the particular construction of the valve control may be of any conventional and well known material.

From the foregoing, the construction and operation of the device will be lreadily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimed as new is as follows:

l. A trench digger comprising a frame, tracks located at opposite sides of the frame, transverse tubular members rigid with said frame, track supporting members slidably supported in said tubular members with the outer ends supporting said tracks, a pair of driven rotatable members mounted on lsaid frame, each of said rotatable members having a central polygonal aperture, polygonal axles drivingly connected with the tracks and slidably received in the polygonal apertures whereby the tracks may be moved laterally a distance substantially equal to the length of the axles, and a fluid pressure actuated piston and cylinder arrangement interconnecting the tracks and the frame for laterally adjusting the tracks at any time by actuating the piston and cylinder arrangement, said tubular members, track supporting members, axles, and driven members lbeing disposed in staggered relation whereby the entire length thereof is utilized in effecting adjustment of the tracks and support thereof after adjustment thereby enabling the use of a minimum width frame.

2. The structure as defined in claim l wherein said frame is provided with a rearwardly extending boom, means pivotally and vertically adjustably supporting the forward end of the boom from the frame, power operated cable means interconnecting the rear end of the boom and frame for supporting the rear end of the same and raising and lowering the rear end of the boom, and power operated ditching mechanism mounted on said boom for digging a ditch as the frame is propelled.

3. The structure as defined in claim 2 wherein said ditching mechanism includes a rotary ditcher wheel having a plurality of radially extending and circumferentially spaced tapered |buckets mounted thereon for digging a tapered ditch, and laterally extending, power operated conveyor means mounted on the boom and receiving the excavated earth from the buckets and discharging the same laterally voutwardly of the frame and tracks.

References Cited in the le of this patent UNITED STATES PATENTS 1,321,107 Kidney Nov. 11, 1919 1,589,783 Arndt June 22, 1926 1,710,116 Sembera Apr. 23, 1929 1,852,048 George Apr. 5, 1932 1,877,556 Clark et al. Sept. 13, 1932 1,974,190 Miller Sept. 18, 1934 2,256,719 Liebing et al. Sept. 23, 1941 2,321,352 Askue June 8, 1943 2,329,659 Smith Sept. 14, 1943 2,421,904 Penote .Tune l0, 1947 2,488,016 Lado Nov. 15, 1949 2,598,339 Askue May 27, 1952 2,652,641 Zowaski Sept. 22, 1953 2,681,231 Kondracki .Tune 15, 1954 2,709,859 Pilch June 7, 1955 

